The present invention relates to a connector arranged for double retention of terminal fittings to a connector housing by use of a front holder.
Japanese Unexamined Patent Publication No. 9(1997)-106847 discloses a connector of the foregoing type as shown in FIGS. 1 to 5. A housing 1 of this connector is composed of a housing body 2 including a right-and-left pair of tubular portions 3 and 3 for housing terminal fittings 9 to which electric wires 7 and rubber plugs 8 are attached by pressure, and a front holder 5 attached to a front side of outer peripheral faces of peripheral walls of the pair of tubular portions 3 and 3. On a back side of the outer peripheral faces of the peripheral walls of the pair of tubular portions 3 and 3, an annular waterproof packing 6 is embedded. A T-shaped notch 3a is formed in the center of an upper front side of the peripheral wall of each tubular portion 3. Inside the notch 3a, provided is a flexible lance 4 for retaining the terminal fitting 9.
Upon assembly of this connector 1, a pair of retaining protrusions 5b and 5b respectively on the right and the left inside the front holder 5 are fitted into tips of long holes 3b provided on both sides of the peripheral wall of the tubular portions 3, whereby the front holder 5 is temporarily attached (temporarily retained) to the respective tubular portions 3 in front of flexure deformation regions of the flexible lances 4 (see FIGS. 3 and 4). In this event, each of the retaining protrusions 5a on both of the upper faces of the front holder 5 is striking a tip of each tubular portion 3 of the housing body 2 to prevent the front holder 5 from being pushed further inward. In other words, the front holder 5 is held in a temporary retention position owing to a state that the retaining protrusions 5b are fitted into the long holes 3b, and to a state that the retaining protrusions 5b are striking the tips of the tubular portions 3.
Next, the terminal fittings 9 to which the electric wires 7 and the rubber plugs 8 are attached by pressure are housed in the respective tubular portions 3 from the back side of the housing body 2, and the terminal fittings 9 are subjected to primary retention inside the respective tubular portions 3 with the flexible lances 4. Subsequently, from the above-described state, the front holder 5 is further pushed into a full retention position (see FIG. 5). Then, the respective retaining protrusions 5a on the both upper sides of the front holder 5 are fitted into the notches 3a of the respective tubular portions 3 (see FIG. 1), and an upper wall of the front holder 5 (which corresponds to a lance support) intrudes into the flexure deformation regions of the respective flexible lances 4, whereby the front holder 5 is fully attached (fully retained) to the tubular portions 3. In this way, flexure deformation of the respective flexible lances 4 is regulated, whereby the respective terminal fittings 9 are doubly retained.
Note that, in the foregoing connector, an abutting plane of the temporarily retaining protrusion 5a with respect to the tip of the tubular portion 3 is composed of an inclined plane having an angle 1 in an unlocking direction (see FIG. 2), in order to generate component force in the event that an assembly operator pushes the front holder 5 located in the temporary retention position of FIG. 4 into the full retention position of FIG. 5 by fingers.
Nevertheless, the above-described inclined plane of the temporarily retaining protrusion 5a is designed to generate the component force in the direction of the inclined plane to a degree pushable by fingers. Accordingly, when transportation or transfer takes place in an assembly state that the front holder 5 is temporarily retained, a problem would occur that the front holder 5 is pushed into the full retention position by a shock or dropping.
The present invention is made in consideration of the foregoing circumstance. An object of the present invention is to provide a connector arranged for preventing a front holder of the connector in a temporary retention position from being pushed into a full retention position easily.
In a first aspect of the present invention, a connector housing is composed of a housing body to which terminal fittings are inserted from a back side thereof, and a holder to be engaged with the housing body from the front side thereof. The holder is made pushable from a temporary retention position short of the housing body toward a full retention position on a back side. Between the housing body an the holder, provided are temporary retention means for temporarily retaining the holder in the temporary retention position, and full retention means for fully retaining the holder in the full retention position. On any one of the housing body and the holder, provided is a flexible lance or arm for retaining a terminal fitting inserted from a back side of the connector housing for preventing extraction, in a state that the holder is located in the temporary retention position. On the other one of the housing body and the holder, provided a lance or arm support for inhibiting the flexure of the flexible lance by intruding into a flexure allowable space of the flexible lance when the terminal fitting is pushed from the temporary retention position into the full retention position in the state that the terminal fitting is retained by the flexible lance to prevent extraction, whereby the terminal fitting is doubly retained. In a connector of the above described constitution, the temporary retention means strengthens retention when pushing force is applied to the holder. Also, the connector is characterized by a constitution that retention is released upon insertion of a retention release jig from the front side of the connector housing.
In the case of assembling this connector, firstly, the front holder is fitted into the housing body, and the front holder is temporarily retained in the temporary retention position by the temporary retention means. When pushing force acts on the front holder in this state of temporary retention, the temporary retention means acts in a direction to strengthen the retention. In other words, the front holder will be completely locked. Accordingly, temporary retention will not be released, whereby the front holder will be avoided from being pushed from the temporary retention position into the full retention position accidentally upon transportation or transfer.
In this state of temporary retention, the terminal fitting is inserted from the back side of the connector housing, and the terminal fitting is retained by the flexible lance to prevent extraction. Subsequently, while releasing temporary retention by inserting the retention release jig from the front side of the connector housing, the front holder is pushed from the temporary retention position into the full retention position. Then, the lance support intrudes into the flexure-allowable space of the flexible lance, thus inhibiting flexure of the flexible lance. By pulling out the retention release jig simultaneously with the above action, the front holder is fully retained on the housing body by the full retention means. In this way, the connector with the doubly retained terminal fitting is finished.
A second aspect of the present invention is the connector according to the above-described first aspect, in which the temporary retention means includes a retention arm provided resiliently deformable on either one of the housing body or the front holder, and a retaining protrusion to be formed on the other one of the housing body or the front holder for temporarily retaining the front holder in the temporary retention position by abutting on a tip of the retention arm. Here, the connector is characterized in that an inclination is provided at least on one of the tip of the retention arm and an abutting plane of the retaining protrusion for generating a biting action reverse to a direction to release retention when pushing force is applied to the front holder.
In this connector, when the pushing force acts on the temporarily retained front holder, bites are generated in the direction of strengthening the retention between the retention arm and the retaining protrusion because of a function of the inclined abutting plane. Accordingly, the retention arm will not be released from the retaining protrusion but a complete lock is achieved, whereby the front holder will be avoided from being pushed into the full retention position accidentally upon transportation or transfer. In order to release the state of temporary retention of this connector, the tip of the retention arm may be released from an abutting position on the retaining protrusion by deforming the tip of the retention arm with the retention release jig inserted from the front side of the connector housing.
A third aspect of the present invention is the connector according to the above-described second aspect, in which the retaining protrusion is provided on the front holder, and the retention arm is provided on the housing body in a manner that the tip, which is a free end, is directed to the front, and a jig insertion hole is provided on the front holder for inserting the retention release jib from the front side of the front holder.
In order to release temporary retention of the front holder of this connector, the retention release jig is inserted from the jig insertion hole of the front holder to release the tip from the abutting position on the retaining protrusion by deforming the tip of the retention arm toward a releasing direction, and the front holder is pushed in simultaneously. Temporary retention can be released by the foregoing operation.
A fourth aspect of the present invention is the connector according to the above-described second aspect, in which the retaining protrusion and the retention arm serve as both the temporary retention means and the full retention means, and a concave portion for engagement is provided on the retention arm for allowing the retaining protrusion to be fitted therein in order to achieve full retention.
In this connector, full retention can be achieved by releasing temporary retention owing to abutment of the tip of the retention arm and the retaining protrusion with a jig, and subsequently by fitting the retaining protrusion into the concave portion for engagement.
A fifth aspect of the present invention is the connector according to the above-described fourth aspect, in which an engaging protrusion is provided, aside from the foregoing retaining protrusion, for preventing extraction toward the front side of the front holder upon temporary retention of the front holder by fitting into the concave portion for engagement provided on the retention arm.
In this connector, the front holder can be securely held not to jolt back and forth upon temporary retention thereof by functions of the retaining protrusion, the engaging protrusion and the retention arm.
A sixth aspect of the present invention is the connector according to the above-described first aspect, in which a waterproof plug is provided between a terminal insertion hole formed on the housing body and an electric wire extending backward from the terminal fitting, for sealing a gap between the terminal insertion hole and the electric wire, and a packing is provided on the housing body for sealing a gap between the connector and a housing of an opponent connector when the connector is fitted into the opponent connector. The connector is characterized by a waterproof constitution owing to sealing functions of the waterproof plug and the packing.
In the waterproof connector sealing an electric wire outgoing portion with the waterproof plug and sealing a connector fitting portion with the packing, the problem is where a holder for double retention of a terminal fitting is to be attached from. However, since the connector of the present invention adopts a mode of attaching a holder (the front holder) from the front thereof, the connector can adopt a compact constitution while maintaining a waterproof structure.
A seventh aspect of the present invention is the connector according to the above-described first aspect, in which a terminal housing chamber is provided on the front holder and the flexible lance is provided on a wall of the terminal housing chamber, and the lance support is provided on the housing body.
In this connector, the terminal fitting inserted from the back side of the connector housing is housed in the terminal housing chamber of the front holder temporarily retained on the housing body. For this reason, the terminal fitting can be subjected to primary retention by the flexible lance. Moreover, the terminal fitting moves together with the front holder when the front holder is moved from the temporary retention position to the full retention position in a state that the terminal fitting is retained. For this reason, it is possible to confirm as to whether a pushing operation to the full retention position of the front holder is surely performed, by visually confirming a position of the terminal fitting or a position of the electric wire extending backward from the terminal fitting.